cfg80211: add get reg command

This lets userspace request to get the currently set
regulatory domain.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 88 insertions, 1 deletions

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 76aae3d8e97e..4bc27049f4e5 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -113,6 +113,8 @@
  * @NL80211_CMD_SET_BSS: Set BSS attributes for BSS identified by
  *      %NL80211_ATTR_IFINDEX.
  *
+ * @NL80211_CMD_GET_REG: ask the wireless core to send us its currently set
+ *      regulatory domain.
  * @NL80211_CMD_SET_REG: Set current regulatory domain. CRDA sends this command
  *      after being queried by the kernel. CRDA replies by sending a regulatory
  *      domain structure which consists of %NL80211_ATTR_REG_ALPHA set to our
@@ -188,6 +190,8 @@ enum nl80211_commands {
 
         NL80211_CMD_SET_MGMT_EXTRA_IE,
 
+        NL80211_CMD_GET_REG,
+
         /* add new commands above here */
 
         /* used to define NL80211_CMD_MAX below */
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index e69da8d20474..d452396006ee 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -2093,6 +2093,81 @@ static int nl80211_set_mesh_params(struct sk_buff *skb, struct genl_info *info)
 
 #undef FILL_IN_MESH_PARAM_IF_SET
 
+static int nl80211_get_reg(struct sk_buff *skb, struct genl_info *info)
+{
+        struct sk_buff *msg;
+        void *hdr = NULL;
+        struct nlattr *nl_reg_rules;
+        unsigned int i;
+        int err = -EINVAL;
+
+        mutex_lock(&cfg80211_drv_mutex);
+
+        if (!cfg80211_regdomain)
+                goto out;
+
+        msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+        if (!msg) {
+                err = -ENOBUFS;
+                goto out;
+        }
+
+        hdr = nl80211hdr_put(msg, info->snd_pid, info->snd_seq, 0,
+                             NL80211_CMD_GET_REG);
+        if (!hdr)
+                goto nla_put_failure;
+
+        NLA_PUT_STRING(msg, NL80211_ATTR_REG_ALPHA2,
+                cfg80211_regdomain->alpha2);
+
+        nl_reg_rules = nla_nest_start(msg, NL80211_ATTR_REG_RULES);
+        if (!nl_reg_rules)
+                goto nla_put_failure;
+
+        for (i = 0; i < cfg80211_regdomain->n_reg_rules; i++) {
+                struct nlattr *nl_reg_rule;
+                const struct ieee80211_reg_rule *reg_rule;
+                const struct ieee80211_freq_range *freq_range;
+                const struct ieee80211_power_rule *power_rule;
+
+                reg_rule = &cfg80211_regdomain->reg_rules[i];
+                freq_range = &reg_rule->freq_range;
+                power_rule = &reg_rule->power_rule;
+
+                nl_reg_rule = nla_nest_start(msg, i);
+                if (!nl_reg_rule)
+                        goto nla_put_failure;
+
+                NLA_PUT_U32(msg, NL80211_ATTR_REG_RULE_FLAGS,
+                        reg_rule->flags);
+                NLA_PUT_U32(msg, NL80211_ATTR_FREQ_RANGE_START,
+                        freq_range->start_freq_khz);
+                NLA_PUT_U32(msg, NL80211_ATTR_FREQ_RANGE_END,
+                        freq_range->end_freq_khz);
+                NLA_PUT_U32(msg, NL80211_ATTR_FREQ_RANGE_MAX_BW,
+                        freq_range->max_bandwidth_khz);
+                NLA_PUT_U32(msg, NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN,
+                        power_rule->max_antenna_gain);
+                NLA_PUT_U32(msg, NL80211_ATTR_POWER_RULE_MAX_EIRP,
+                        power_rule->max_eirp);
+
+                nla_nest_end(msg, nl_reg_rule);
+        }
+
+        nla_nest_end(msg, nl_reg_rules);
+
+        genlmsg_end(msg, hdr);
+        err = genlmsg_unicast(msg, info->snd_pid);
+        goto out;
+
+nla_put_failure:
+        genlmsg_cancel(msg, hdr);
+        err = -EMSGSIZE;
+out:
+        mutex_unlock(&cfg80211_drv_mutex);
+        return err;
+}
+
 static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info)
 {
         struct nlattr *tb[NL80211_REG_RULE_ATTR_MAX + 1];
@@ -2333,6 +2408,12 @@ static struct genl_ops nl80211_ops[] = {
                 .flags = GENL_ADMIN_PERM,
         },
         {
+                .cmd = NL80211_CMD_GET_REG,
+                .doit = nl80211_get_reg,
+                .policy = nl80211_policy,
+                /* can be retrieved by unprivileged users */
+        },
+        {
                 .cmd = NL80211_CMD_SET_REG,
                 .doit = nl80211_set_reg,
                 .policy = nl80211_policy,
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index f643d3981102..2323644330cd 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -57,7 +57,7 @@ static u32 supported_bandwidths[] = {
 /* Central wireless core regulatory domains, we only need two,
  * the current one and a world regulatory domain in case we have no
  * information to give us an alpha2 */
-static const struct ieee80211_regdomain *cfg80211_regdomain;
+const struct ieee80211_regdomain *cfg80211_regdomain;
 
 /* We use this as a place for the rd structure built from the
  * last parsed country IE to rest until CRDA gets back to us with
diff --git a/net/wireless/reg.h b/net/wireless/reg.h
index eb1dd5bc9b27..fe8c83f34fb7 100644
--- a/net/wireless/reg.h
+++ b/net/wireless/reg.h
@@ -1,6 +1,8 @@
 #ifndef __NET_WIRELESS_REG_H
 #define __NET_WIRELESS_REG_H
 
+extern const struct ieee80211_regdomain *cfg80211_regdomain;
+
 bool is_world_regdom(const char *alpha2);
 bool reg_is_valid_request(const char *alpha2);